. The drug plants of Illinois . A large, specially constructed drying house for drug plants. The fresh plants are spread on trays like those shown in the drawing on page 5, and the loaded trays are carried in through the doors and stacked one above another. A furnace in the basement supplies a continuous current of warm, dry air which absorbs moisture from the plants and carries it out through the ventilating structure at the top. (After United States Department of Agriculture Farmers' Bulletin 1231.) herbs or 2,000 pounds of fresh roots. Directions for the construction of special equipment of
. The drug plants of Illinois . A large, specially constructed drying house for drug plants. The fresh plants are spread on trays like those shown in the drawing on page 5, and the loaded trays are carried in through the doors and stacked one above another. A furnace in the basement supplies a continuous current of warm, dry air which absorbs moisture from the plants and carries it out through the ventilating structure at the top. (After United States Department of Agriculture Farmers' Bulletin 1231.) herbs or 2,000 pounds of fresh roots. Directions for the construction of special equipment of this kind are given in United States Department of Agriculture Farmers' Bulletin 1231. In the use of artificial heat, best results are obtained if a few funda- mental principles are observed. Free circulation of the heated air must be provided in such a way that water-laden air is being continually discharged from the drying chamber and constantly replaced by fresh, dry, warm air. A high drying temperature must not be used. Plants and plant parts con- taining volatile oils lose much of their oil content at high temperatures and, therefore, throughout the drying process should be kept at a temperature not greatly exceeding that of the outside air. With most other plants, the temperature can be increased gradually, as the plants dry, until it reaches 120 degrees F., or, with most barks, 170 degrees F. Two emphatic exceptions must be made to the general statements in the 1
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Keywords: ., boo, bookcentury1900, booksubjectbotany, booksubjectbotanymedical
